Timeline for What is the 31st homotopy group of the 2-sphere?
Current License: CC BY-SA 4.0
23 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 25, 2021 at 1:16 | comment | added | LSpice | Your link to the article of Berrick, Cohen, Wong, and Wu was broken. I have changed it to the published version while this is on the front page. | |
| Aug 25, 2021 at 1:15 | history | edited | LSpice | CC BY-SA 4.0 |
Names of articles
|
| Aug 24, 2021 at 21:16 | answer | added | Tyler Lawson | timeline score: 38 | |
| S Aug 22, 2021 at 1:01 | history | bounty ended | CommunityBot | ||
| S Aug 22, 2021 at 1:01 | history | notice removed | CommunityBot | ||
| Aug 14, 2021 at 2:45 | history | edited | Gerry Myerson | CC BY-SA 4.0 |
typos
|
| S Aug 13, 2021 at 23:42 | history | bounty started | Emily | ||
| S Aug 13, 2021 at 23:42 | history | notice added | Emily | Draw attention | |
| Apr 13, 2017 at 12:19 | history | edited | CommunityBot |
replaced http://math.stackexchange.com/ with https://math.stackexchange.com/
|
|
| May 17, 2013 at 9:04 | answer | added | Mark Grant | timeline score: 33 | |
| May 17, 2013 at 8:45 | comment | added | Trimok | @Mariano : I understand you, but there are also a lot of mathematical books, where the interesting ideas or philosophy are not highlighted, because it is hidden in a too formal or technical presentation. And, in mathematics or physics, the important things are ideas. | |
| May 17, 2013 at 8:31 | comment | added | Mariano Suárez-Álvarez | «For separable states, the original Hilbert space $S^7$ simplifies to $S^2\times S^2$» Reading physics papers requires a lot of restraint :-) | |
| May 17, 2013 at 8:27 | comment | added | Christian Nassau | Actually, I remember seeing more unstable charts in the "Oaxtapec proceedings" (CONM146) (Appendix 2 by Paul Shick), but I don't know if this relates to $S^2$. Be warned that it's usually nontrivial to deduce the homotopy from these charts, so this info might not be of much use to you. | |
| May 17, 2013 at 8:16 | comment | added | Trimok | @Christian Nassau : Thanks for the reference (I am going to see it I am able to extract information from this paper) | |
| May 17, 2013 at 8:08 | comment | added | Christian Nassau | You could deduce some information on $\pi_{32}(S^3)$ from Bob Bruners unstable chart on the bottom of math.wayne.edu/~rrb/cohom/index.html (if that's of any help) | |
| May 17, 2013 at 8:00 | comment | added | David Roberts♦ | Ah, how embarrassing.... :-S | |
| May 17, 2013 at 7:54 | comment | added | Neil Strickland | @David: $\pi_{31}(S^2)$ is well out of the stable range. There is a homomorphism to the 29th stable group, but it is unlikely to be injective or surjective. | |
| May 17, 2013 at 7:53 | comment | added | Trimok | @David Roberts : Thanks, have you a reference, please ? | |
| May 17, 2013 at 7:50 | comment | added | Trimok | Yes, I know, but it is however possible, that there exists a link between this 31th homotopy group of the 2-sphere, and classification of 4-qbits entanglements. | |
| May 17, 2013 at 7:45 | comment | added | Mariano Suárez-Álvarez | But there is no fourth Hopf fibration! | |
| May 17, 2013 at 7:39 | comment | added | Trimok | In the reference physics article, it is explained that, in a Hopf fibration, the base space (S4,S8) contains information about one qbit, and the entanglement with the others qbits. If there is no entanglement, this reduces to S2. The third Hopf fibration explains 3-qbits entanglement, so it is hoped that sedenions (so S31) could explain 4-qbits entanglement. | |
| May 17, 2013 at 7:34 | comment | added | Mariano Suárez-Álvarez | In what way the two things you list as motivation are motivation for asking what the 31st homotopy group is? | |
| May 17, 2013 at 7:33 | history | asked | Trimok | CC BY-SA 3.0 |